The invention relates to a teat unit.
The best known teat unit for a baby's feeding bottle has a ring with an inner thread, and a teat extending through this ring. The teat has a substantially frustoconical main body which, at the narrower end, merges into a substantially cylindrical mouthpiece. Formed integrally on the broader end of the main body there is a flange which, by virtue of the threaded ring, bears sealingly on the neck of the bottle. This unit is inexpensive, easy to clean and easy to handle, but it is greatly limited in terms of its possible variations and as a result is unable in particular to meet the requirements of premature babies or infants who have difficulties drinking.
In U.S. Pat. No. 5,553,726, a valve is inserted in the transition area between mouthpiece and main body.
WO 2007/053894 discloses a three-part teat unit for a baby's bottle. Here too, a threaded ring and a teat are provided. The third part is a plate, which is fitted onto the neck of the bottle. The teat is arranged above the plate, and both parts are held in their position by the threaded ring. The plate has openings which, depending on the position of rotation of the threaded ring, form a passage to the teat or are closed by the threaded ring.
In U.S. Pat. No. 5,791,503, a similar arrangement is used to allow air into the bottle during the pauses when the baby is not sucking.
US 2004/0035815 describes a drinking cup with teat for young children. The teat and a valve element are held in a lid of the cup by means of a threaded ring, said threaded ring pressing from outside onto a flange of the teat, and the flange bearing with its inner surface on the valve element. The valve element in turn sits on a shoulder of the lid.
US 2005/0224444, U.S. Pat. No. 2,584,359, EP 0 384 394 and EP 1 416 900 also disclose teats that extend through a threaded ring and are held sealingly by the latter on a baby's bottle. The third part is in each case a valve body, which bears with a flange on the neck of the bottle, extends into the interior of the teat and is likewise held in its sealing position by the threaded ring.
A teat unit with a complex construction is disclosed in WO 97/04735, the teat in this case too being held on the bottle by a one-piece threaded ring.
WO 2007/137440 discloses a teat unit with a one-piece or two-piece teat and with a dimensionally stable receiving head for receiving the teat. The one-piece receiving head is provided with a threaded ring, such that it can be screwed onto the neck of a baby's bottle or a drinking cup. The teat is fitted on the semi-spherical receiving head and is not secured with the threaded ring.
In U.S. Pat. No. 1,605,427, the teat is fitted on the neck of the bottle directly, i.e. without an intermediate ring. The mouthpiece of the teat is strengthened by an insert part. In BE 381 523 also, the teat is fitted directly on the neck of the bottle.
U.S. Pat. No. 7,225,938 discloses a teat unit in which an intermediate chamber with a valve is screwed onto the baby's bottle. The known threaded ring, with the teat extending through it, is then screwed onto this intermediate chamber.
WO 99/22693 discloses a teat unit with a threaded ring and a two-piece suction body extending through the latter. The threaded ring is screwed with its inner thread onto an adapter part which has an inner thread and outer thread and which is secured with its inner thread on a neck of a baby's bottle.
Although these known solutions in each case optimize one of the following five functions, they at the same time detract from at least one of the other four functions;                optimal milk flow,        reliable closing and opening at a specific predetermined pressure, in the case where a valve is used,        optimal venting during the pauses when the baby is not sucking,        simple securing of the teat, and simple removing of same from the rest of the teat unit and from the bottle, and simple cleaning, and        optimal interface with the baby's mouth by virtue of the suitable elasticity of the teat unit.        
The known solutions also have one or more of the following disadvantages:                they are of a complicated structure and are therefore expensive to produce,        the teat has to be designed with a relatively thick wall, which in turn makes production more difficult and increases costs, and        they can be used only in a single configuration and do not permit any variations.        